Many image sensing applications require sensor nodes to operate in remote and isolated areas for long periods of time. In these scenarios, the sensor nodes might not have access to the electric grid to recharge their batteries. Moreover, due to their remote location, replacing the batteries of these sensors will be very costly and in some instances even prohibitive. In these cases harvesting energy from the sensor's environment is an appealing solution which could eliminate battery replacement and enable long term operation of the sensor.
Sources of ambient energy can be as diverse as solar, thermal, wind, vibrations and electro-magnetic fields. Solar is one of the most abundant sources of energy in the planet and is especially suitable in outdoor monitoring scenarios where power densities can reach up to 100 mW/cm2. Prior art image sensing systems provide various methods for harvesting energy from imaging sensing pixels. However, these systems are bulky, expensive, and overly complex. Therefore, improvements are needed in the field.